Acne is one of the most common skin conditions seen in general practice. Acne vulgaris – the most prevalent form – affects more than 80% of teenagers and young adults (in some countries, it may be as many as 95%), and tends to peak around age 18.

But acne isn’t a single condition. It appears in many forms, affects people at different ages, and can be triggered by a range of factors. Acne-like rosacea, for example, is more common in fair-skinned, middle-aged adults.

Acne may also arise from hormonal changes, exposure to certain chemicals, medications, or even from your job or hobbies. What all these types of acne share is inflammation of the skin, which produces spots and lesions of different kinds, from mild to severe.

One of the earliest and most familiar spots associated with acne vulgaris are comedones – better known as blackheads and whiteheads. Our skin is lined with tiny glands that secrete oil to keep it soft and protected. When these glands become blocked with oil and debris, they form comedones. Closed comedones appear white, while open ones darken when the clogged material reacts with air.

At this stage, acne is usually mild and non-inflammatory. Over time, however, blocked pores can become irritated and infected. When this happens, comedones can develop into papules (small, raised bumps) or pustules, which are spots filled with pus. These often become red, sore and inflamed, which........

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